Anyone has tried the esp32-bluetooth.bin?
I expect it at least support some basic Bluetooth function but i wasn't successful at guessing the command, it will be helpful if someone can provide some info on how to use the Bluetooth function.

So you might be able to figure out how to use it by reading the examples in the comments and/or looking at the code, but it's going to be tough because the PR is still being updated and I'm not sure how old that firmware is.